Front Blower Motor

The front Blower Motor controls operate by supplying voltage to the motor through switch and relay contacts. Battery voltage is available from HTR-A/C Fuse 12 through the BRN (141) wire to the Heater and A/C Controller when the Ignition Switch is in Run. When the Heater and A/C Controller's Mode Switch is in the Defrost. Blend, Heat, Vent, Bi-Level, A/C, or MAX A/C positions, this voltage is available through the WHT (119) wire to the Heater and A/C Controller's Blower Motor Switch. This voltage provides for operation of the Blower Motor at LO, Medium 1, and Medium 2 speeds. It also provides for the operation of the Blower Motor Relay in the Blower Motor Resistor/Relay. Battery voltage for Blower Motor HI speed operation is supplied at all times from the BLOWER Fuse through the RED (542) wire to the Blower Motor Resistor/Relay. The Blower Motor and the Blower Motor Resistor/Relay are grounded at Ground G103 by the BLK (150) wire.

Placing the Blower Motor Switch in the LO position applies voltage from the switch contacts through the YEL (60) wire to the Blower Motor Resistor/Relay. The Blower Motor Relay remains de-energized and voltage is available through the three resistors to the Blower Motor. Since the Blower Motor is grounded through the Blower Motor Resistor/Relay, current flow is established and the Blower Motor operates. Voltage drop through the three resistors in the Blower Motor Resistor limits motor operation to it's lowest speed.

Placing the Blower Motor Switch in the Medium 1 position applies voltage to the Blower Motor Resistor/Relay through the TAN (63) wire. Current must flow through only two resistors to get to the motor. With the increased voltage at the motor, the motor operates at a faster speed.

Placing the Blower Motor Switch in the Medium 2 position applies voltage to the Blower Motor Resistor/Relay through the LT BLU (72) wire. Current must flow through only one resistor to get to the motor. With the increased voltage at the motor, the motor operates at a still faster speed.

Automatic reset thermal fuses are provided in the Blower Motor Resistor for each resistor. These thermal fuses will open automatically upon high current flow. When the current stops, the fuse cools down and resets automatically.

Placing the Blower Motor Switch in the III position applies voltage through the ORN (52) wire to the Blower Motor Relay coil in the Blower Motor Resistor/Relay. Since the coil is grounded at Ground G103 by the BLK(150) wire, the relay coil energizes. This closes the relay contacts and applies voltage from the BLOWER Fuse Fuse to the Blower Motor. Since there is no voltage drop through any resistors, the Blower Motor operates at it's highest speed.